This invention relates to pipe cleaning apparatus, particularly, to an apparatus for cleaning large diameter pipe forming a fresh or salt water system.
It is well known that the cleaning, repair and inspection of large diameter pipelines is a very difficult, expensive and time consuming task. Various devices and processes have been developed to aid in the removal of marine growth and other foreign material from pipelines of municipal water systems or the like. These prior art devices and methods have met with varying degrees of success. However, none have provided totally satisfactory results. Almost every pipeline, regardless of whether it is in salt water or fresh water, will have some type of marine growth. Therefore, cleaning, repairing and inspection of pipelines is a continual problem faced by pipeline operators and municipalities.
One prior art method of cleaning large diameter pipelines uses the Phosmarine Brush-Cart, an apparatus similar to apparatus used to clean super tankers. The Brush-Cart has several brushes on its under surface that form a suction for engaging the pipeline wall. The Brush-Cart is guided by a diver the full length of the pipeline. This is a very time consuming procedure because the cart only cleans approximately three feet of the inside diameter of the pipeline with each pass. For a pipeline having a twelve foot inside diameter, the Brush-Cart must be run the full length of the pipeline six to eight times to completely clean the pipeline. Another disadvantage associated with the Phosmarine Brush-Cart method of cleaning pipelines is that divers are required to guide or steer the Brush-Cart along the pipeline. Also, the divers require a long period of time for decompression, which is both dangerous to the divers and increases the cost of the pipe cleaning operation. After the marine growth or other foreign material has been removed from the wall of the pipeline, the debris must be moved to the end of the pipeline and then air lifted or otherwise removed from the pipeline. Removal of the debris can often take much longer than the cleaning operation itself. The final step is inspection of the pipeline which is usually done by a diver walking the length of the pipe with a video camera. This is a time consuming procedure and results only in a spot check of the pipeline.
The hydrolaser has also been used to clean pipelines. The hydrolaser is a steel frame mounted on skids having six high pressure water jets to clean the growth or other debris in the pipeline. A disadvantage associated with this method of pipe cleaning is that the high pressure water jets also tend to cut or abrade the walls of the pipeline. In addition, after use of the hydrolaser, the loose debris must be removed from the pipeline, thereby adding to the duration and expense of the cleaning operation.
Pipelines have also been cleaned by divers using hand-held hydraulic cutter heads. This method cleans the growth and removes the foot print from the walls without doing damage to the pipe. If the foot print is not removed, barnacles will grow back in half the time. Removal of loose debris is accomplished by divers with air lifts. Inspection is done by a diver walking within the pipeline with a hand-held video camera. Because of the adverse working conditions, it is difficult for divers to completely clean the pipeline using hand-held hydraulic cutter heads.
It is, therefore, an important object of this invention to provide a multi-functional apparatus for cleaning pipelines and removing debris in one pass of the pipeline.
Another object of the invention is to provide for inspection of the pipeline via color video camera with video tape or still photographs. On site inspection is provided by a one-atmosphere capsule adapted to transport up to three divers for visual inspection of the pipeline.
Still another object of the invention is to provide safe on-site diver support for up to three divers conducting operations in the pipeline. In addition, it is an object of the invention to provide transport for personnel to and from the work site in a warm, dry environment, thereby greatly increasing diver production.